A Research On The Protective Effect Of L-carnitine On Myocardium In Off-pump Coronary Artery Bypass Grafting

Background China has witnessed an evident rise in patients affected by cardiovascular disease,with an increase in mobility and mortality from coronary disease year by year.At present,Coronary Artery Bypass Grafting(CABG)is widely accepted as the most efficient treatment.In China,since the first Conventional Coronary Artery Bypass Grafting(CCABG)was successfully employed in 1974,it rapidly becomes a basic coronary surgery.Considering the deficiencies of CCSBG,OPCABG has been developed and quickly prevailed,being the major coronary operation.According to the research,though OPCABG has improved the cardiac reperfusion,cardiac reperfusion performed when the heart is in ischemia can't help the heart resumes its function but exacerbate cardiac dysfunction,or ischemia-reperfusion injury.Objective Study the protective effect of levocarnitine on myocardium in OPCABG and probe its mechanism.Method I chose 40 patients affected by coronary disease who intended to receive OPCABG in cardiothoracic surgery department from January through December,2016 and divided them at random to Group L(L refers to l-carnitine)with 21 patients and Group C(control group)with 19 patients.The radial artery blood of all patients were drawn at five specific time—T1(before skin incision),T2(after bypass grafts became unblocked),T3(4 hours after the operation),T4(12 hours after the surgery)and T5(24 hours after the surgery)—to measure the amount of cardiac troponin I(c Tn I),creatine kinase-MB(CK-MB) and superoxide dismutase(SOD).Before the chest was closed,a little cardiac muscle tissue of auricula dextra was clipped to successively observe its morphological structure by light microscope and ultrastructure by electron microscope.The amount of bridge vessels,the time of operation,patients' ICU staying and mechanical ventilation and the dosage of positive inotropic drugs within 48 hours after the operation were recorded.Results 1.There was no disparity between the two groups in the amount of bypass grafts,time of operation,staying in ICU and hospital(P>0.05);Group L spent less time in mechanical ventilation and had lower arrhythmia rate than Group C,which is of statistical significance(P<0.05).2.Group L consumed less positive inotropic drugs than Group C within 48 hours after the surgery,which is statistically significant.3.No distinct difference in CK-MB and c Tn I between the two groups were found before the surgery(P>0.05).However,after the operation,the amount of c Tn I and CK-MB of both Group L and Group C raised substantially at T2,T3,T4 and T5,with the quantity of former lower than that of the later.4.Before the surgery,the gap in SOD between the two groups is of no statistical significance(P>0.05).The amount of the SOD of both Group L and Group C obviously decreased at T2,T3,T4 and T5(P<0.05),with the SOD quantity of the former substantially higher than that of the later.5.The cardiac muscular tissue damage of Group L is better than that of Group C,which is statistically significant(P<0.05).Conclusions 1.L-carnitine before the OPCABG is conducive to lightening the damage caused by cardiac reperfusion so as to protect the myocardial cells.2.L-carnitine plays a role in protecting the patient's myocardium may because it can regulate the energy and substance metabolism of the myocardium and make the SOD more active.